Synonyms: Eimeria brumpti, Eimeria jalina, Eimeria suis.
Location: Small intestine, and, to a lesser extent, large intestine.
Geographic Distribution: Worldwide.
Prevalence: E. debliecki is the commonest coccidium of swine. De Graff (1925) found it in 51% of 500 pigs in the Netherlands. Yakimoff et al. (1936) found it in 92% of 141 pigs in Russia. Yakimoff (1936) found it in 27% of 53 pigs from Brazil. Novicky (1945) found it in 27% of 62 pigs in Venezuela. Nieschulz and Ponto (1927) found it in all of about 50 pigs in Java.
Morphology: The oocysts are ovoid to ellipsoidal or subspherical, 13 to 29 by 13 to 19 u. The oocyst wall is 1.0 to 1.5 u thick, smooth, colorless to brownish, and composed of 2 layers. A micropyle is absent. An oocyst polar granule is absent (present according to Paichuk, 1953). An oocyst residuum is absent. The sporocysts are ellipsoidal or ovoid, 14 to 18 by 6 to 8 u with a Stieda body. A sporocyst residuum is present. The sporulation time is 6 to 9 days. The sporulation process has been described in detail by de Graaf (1925).
Life Cycle: De Graaf (1925) and others have described the endogenous stages of this species. The schizonts produce 14 to 16 banana-shaped merozoites. These are 8 to 10 u long and 3 to 4.5 u wide; one end is rounded and the other pointed. The nucleus is usually in the middle of the merozoites. The microgametocytes are 7 to 22 u in diameter when mature. The microgametes are 3.5 u long and 0.6 u wide and have 2 flagella. The macrogametes are similar to those of other Eimeria species.
Biester and Schwarte (1932) found that the prepatent period in experimentally infected pigs was about 7 days and that oocysts were present in the feces for 10 to 15 days in the absence of reinfection.
Pathogenesis: E. debliecki is only slightly pathogenic if at all in adult animals, but it may cause diarrhea and even death in young pigs. Biester and Murray (1929) found that young pigs fed large numbers of sporulated oocysts developed severe diarrhea. They became emaciated and some even died. Some had constipation, but dysentery was never observed. The pigs which recovered usually failed to do well. Alicata and Willett (1946) found that pigs experimentally infected with 20 to 30 million mixed sporulated oocysts of E. debliecki and E. scabra developed a profuse diarrhea lasting 2 to 15 days, inappetance and did not gain weight. Swanson and Kates (1940) described an outbreak of coccidiosis in a litter of 4.5 month old pigs in Georgia. The pigs had a profuse diarrhea and gained weight poorly despite ravenous appetites, excellent rations and good care. Novicky (1945) described several outbreaks of swine coccidiosis in Venezuela. The mortality was relatively low, but the young animals which survived were retarded.
Immunity: Biester and Schwarte (1932) produced complete immunity in pigs by feeding them oocysts daily for 100 days or more. Light infections produced partial immunity. As with other coccidia, adult pigs are often carriers, shedding a few oocysts in their feces.
Remarks: Brug (1946) found E. debliecki as a pseudoparasite of man in Holland. Four out of 13 persons in a psychiatric ward passed oocysts in their feces on one day. They had probably been ingested with liver sausage, the casing of which was made from pig intestines.